1. Field of the Invention
The present invention relates to an apparatus for transferring a pickup of a disc drive. More particularly, the present invention is related to an apparatus which can stably transfer a pickup of a disc drive.
2. Description of the Related Art
In general, disc drives record information onto a disc such as a CD or DVD, or reproduce recorded information from a disc. The disc drive includes a pickup to record information or reproduce recorded information by emitting light on a recording surface of a rotating disc while sliding in a radial direction of the disc, and a pickup transferring apparatus which transfers the pickup.
FIG. 1 is a plan view illustrating a pickup assembly of a disc drive adopting a conventional pickup transferring apparatus. FIG. 2 is an exploded perspective view illustrating the pickup transferring apparatus shown in FIG. 1.
Referring to FIGS. 1 and 2, the disc drive includes a pickup deck 10 on which a spindle motor 20 and a pickup 30 are installed. The spindle motor 20 rotates a disc and the pickup 30 performs recording and reproduction of data by emitting light on a recording surface of the disc. The pickup deck 10 is typically installed on a disc tray (not shown) carrying a disc in a slim disc drive adopted in a notebook computer, or at a main frame forming a housing in a typical disc drive. A turntable 22 where the disc is placed is provided on an upper portion of the spindle motor 20. Various optical elements including an objective lens 32 are provided at the pickup 30.
The pickup 30 emits light onto the recording surface of the disc while moving in the radial direction of the disc. A pickup transferring apparatus is installed on the pickup deck 10. The pickup transferring apparatus includes a lead screw 46 rotatably installed at one side of the pickup deck 10 and a slider 48 fixedly installed on the pickup 30 to convert a rotational motion of the lead screw 46 to a linear motion of the pickup 30.
The lead screw 46 is rotated by receiving power from a drive motor 42 via connection gears 44. A plurality of protruding portions 48a engaged with screw grooves of the lead screw 46 are formed on a lower surface of the slider 48. A leaf spring 50 which applies an elastic force in a direction to press the upper surface of the slider 48 from the upside so that the slider 48 and the lead screw 46 closely contact each other is installed on the upper portion of the slider 48. A guide shaft 52 guiding the linear movement of the pickup 30 is installed at the other side of the pickup deck 10 parallel to the lead screw 46.
In the above structure, when the lead screw 46 is rotated by receiving power from the drive motor 42, the pickup 30 performs a linear motion by the protruding portions 48a of the slider 48 engaged with the screw grooves of the lead screw 46.
However, in the pickup transferring apparatus, when an external impact is applied to the disc drive, the slide 48 slides so that the protruding portions 48a are seated on a plurality of screw threads 46a, as shown in FIG. 3. In this case, the force of the leaf spring 50 can be greater than a driving force of the drive motor 42 so that the pickup 30 is not transferred. When the force of the leaf spring 50 is reduced, although the above problem may be solved, a backlash is generated due to a gap between the pickup 30 and the lead screw 46 so that the pickup 30 is moved unstably.